Synthesis and optical properties of ZnO nanostructures with different morphologies

ZnO nanostructures with different morphologies were grown by a low-temperature hydrothermal technique. The morphology, crystallinity and defect content in the nanostructures could be controlled by adjusting the synthesis conditions. Nanostructures prepared with optimum growth conditions were of good structural and optical qualities. Effects of growth conditions and thermal annealing on the optical properties of the nanostructures were studied by Raman and photoluminescence spectroscopy techniques. It is found that the nanostructures grown with particular initial and final pH values of the reaction mixture and air-annealed at about 250 °C are of best crystalline and optical quality.